In Metropolitan Area Networks (MANS) Wide Area networks (WANs) and the like, fiber optic rings are widely deployed. These rings typically use protocols that are neither optimized nor scalable to the demands of packet networks, including speed of deployment, bandwidth allocation and throughput, resiliency to faults, and reduced equipment and operational costs. The IEEE 802.17 Resilient Packet Ring Working Group (RPRWG) develops standards to support the development and deployment of Resilient Packet Ring (RPR) networks in Local, Metropolitan, and Wide Area Networks for resilient and efficient transfer of data packets at rates scalable to many gigabits per second. These standards build upon existing Physical Layer specifications, and develop new PHYs where appropriate. The two protection methods, wrapping and steering, used in the IEEE 802.17 Resilient Packet Ring (RPR) provide fast but very inefficient and limited network failure recovery. Due to the increased length of the backup path, RPR suffers from high traffic loss, a decreased throughput-delay performance, and the lack of resilience against multiple link and/or node failures.
Local area Network (LAN) implementations typically using Ethernet, are connected to nodes of ring networks. The Ethernet based passive optical networks (PONs) connected to nodes of a ring network undergo optical-electrical-optical (OEO) conversions, such conversions can act as a bottle-neck in systems, slowing down communications and potentially restricting usable bandwidth. It is desirable to connect PONs to the nodes of a ring network to allow all-optical communication, bypassing the OEO conversions.
Multimedia content distributed over existing communication networks are increasing at a rapid pace. The traffic characterization of such information is greedy and requires special processing in order to be transmitted over existing unreliable networks. Transmission of multimedia content over unreliable or congested networks can result in poor reconstructed media quality. While error resilience techniques have been proposed to partially overcome these problems, such techniques affect compression efficiency. One way to stream video is to encode a given video at a large number of different encoding rates, i.e., into different versions, and then to transmit the version with the highest rate that still fits into an available bandwidth. This approach of transmitting different encoded versions of the same video, also known as simulcast or bit stream switching, while simple, has a number of significant drawbacks. These include the need to encode an impractically large number of versions (on the order of several tens of versions are required to adapt a video encoded at one Megabit per second (Mbps) for transmission at a granularity of 100 kilobit per second (kbps)) and no flexibility to scale down the bit rate/video quality of a stream during network transport, unless typically complex and computationally demanding transcoding is performed at intermediate network nodes. Bitstream switching can also be applied over versions of different coding schemes, but an increase in the computational complexity of video decoding is inevitable.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.